Action bar-action spring link using flexible wire

ABSTRACT

A system for transferring the forces between reciprocably mounted firearm action bars (and a bolt assembly connected thereto) and an action spring mounted in the gun stock. A flexible wire link connects the action spring and the action bars so that rearward movement of the action bars to the breech open position causes biasing of the action spring whereupon the action spring now urges the action bars forwardly to breech closed position.

This invention relates generally to a firearm of the type which isautomatically reloaded and made ready for subsequent firing by eitherutilizing the energy of recoil imparted to a movably mounted barrel, orby utilizing a portion of the explosive gases to move the reciprocatingaction bars and bolt assembly rearwardly into breech open position. Sometypical U.S. Pats. showing firearms of this type are Hepburn, No.918,447; Crittendon, No. 2,570,772; and Saive, No. 2,780,145.

More specifically, this invention relates to a novel system oftransferring the forces between the reciprocably mounted action bars andbolt assembly and an action spring mounted in the gun butt stock.

It is an object of this invention to provide an improved, flexible wirelinkage between the reciprocably mounted action bars and bolt assemblyand an action spring, wherein the action spring is biased by therearward movement of the action bars.

It is a further object of this invention to provide a flexible wirelinkage between the action bars and action spring which will haveadequate part life and which does not take up much space, thus avoidingparts congestion within the frame of the gun.

Other objects and advantages will appear from consideration of thespecification and claims, referring to the attached drawings in which:

FIG. 1 is a side elevation of a portion of a firearm showing the actionin the forward breech closed position.

FIG. 2 is a side elevation of a portion of the firearm shown in FIG. 1showing the action in a breech open position.

FIG. 3 is a plan view of the firearm shown in FIG. 1.

FIG. 4 is a sectional view of the action spring tube showing a modifiedaction spring, in this case an extension spring in place of thecompression spring shown in FIGS. 1-3.

It is to be understood that when the term "automatic firearm" is usedherein that it is the intent that this term includes not only firearmswhich are fully automatic, i.e. will fire continuously as long as thetrigger remains depressed and ammunition is available, but also includessuch firearms which today are sometimes known as "semi-automatic" or"autoloading", i.e. where the trigger must be actuated for each firingcycle. In either case, the action is cocked and made ready to fire byeither utilizing the gun recoil or by using part of the explosive gasesin the barrel to move the action rearwardly after firing.

When the action bars 10 and bolt assembly 12 of an automatic firearm 14are brought to their rearmost position after the firing of a round (seeFIG. 2), some means must be provided for feeding the next cartridge 15into the chamber 15a and for returning the action bars and bolt assemblyto their forward, breech closing position.

An action spring 16 is contained in the action spring tube 18 which ispositioned in stock 19 and which extends from the rear of the gun frame20 to provide the force required to return the action bars 10 and boltassembly 12 to the forward-most or breech closing position. The boltassembly 12, which includes the firing pin (not shown), is mounted tothe action bars 10 and moves therewith reciprocably between the forwardbreech closed position (FIG. 1) to a rearward breech open position (FIG.2). As mentioned above, the force which moves the action bars and boltassembly rearwardly to the breech open position can be provided by gunrecoil or by bleeding off explosive gas pressure from the barrel of thegun. The force which moves the action bars and bolt assembly to aforward breech closed position is provided by the action spring 16.

Thus far, the construction described above is conventional. Moreover,the Hepburn and Crittendon patents, cited above, disclose rigid linksconnecting the action spring and the reciprocating bolts, while theSaive patent, also cited above, discloses a rigid rod link connectingthese parts.

The present invention utilizes a novel flexible wire link 22 to transferthe force of the action spring 16 to the action bars 10 and attachedbolt assembly 12. The forward end of wire link 22 is attached to theaction bars 10 and runs forward through a slot (not shown) in the actionbar to the wire link forward guide pin 24. There it makes a 180° turnand runs rearwardly along the inside surface of the frame 14. Near therear of the frame, it goes around rear wire link guide pins 26, 28, 30,and 32 and enters the action spring tube 18. In its entrance to theaction spring tube, the wire link 22 is guided by an action spring stop34 which, in addition to acting as a stop for the action spring 16,locates the wire link 22 centrally in the action spring tube. The wirelink is then connected to the rear of the action spring by means of awire link connecting washer 36 and a wire link connecting nut 38completing the assembly.

The description outlined above refers to the use of a compression actionspring as shown in FIGS. 1 through 3. It is possible, however, to use anextension type of action spring as shown in FIG. 4.

In the modification shown in FIG. 4, the flexible wire link 22 isconnected at its forward end in the same manner as shown in FIG. 1. Therear end of the wire link enters the action spring tube 18 and is guidedby an action spring stop 34, again as shown in FIG. 1. The wire link 22is then attached to the forward end of an extension spring 40, the rearend of which is connected to the action spring tube by means of anextension spring retainer 42, in this case a cross pin.

As will be understood, when the action moves rearwardly to the breechopen position, the wire link is moved forwardly so that the extensionspring 40 is elongated and put in tension. When the action is at itsrearmost position, the spring 40, supported at its rear end and pulledforwardly at its forward end, is biased to move the wire link rearwardlyand thus to move the action bar and bolt assembly forwardly into breechclosed position.

Flexible wire link 22 can be any type of flexible wire which has highstrength, e.g. impact and wear, characteristics. Generally, thepreferred type will be wire composed of metal strands twisted to form ahigh strength wire, and preferably coated with a suitable plastic, suchas nylon. A nylon coated wire has been successfully tested in an altered12 gauge shotgun. Other plastics, such as fluorcarbon, would also beexpected to be suitable for this purpose.

The nylon coated flexible wire provides for (1) less operating friction;(2) more wear resistance; and (3) greater endurance life of wire.

In addition to the nylon coating assisting in decreasing the amount ofoperating friction, it should be understood that the friction can bedecreased by hardening and polishing the forward guide pin 24 as well asthe wire link guide pins 26, 28, 30, and 32.

The following description of the cycle of operation refers to thepreferred compression type of action spring as shown in FIGS. 1-3.

Our description will begin with the action in its forward-most breechclosed position, as shown in FIG. 1. After the round is fired, theaction, i.e. bars 10 and bolt assembly 12, starts its movement to therear under the influence of gun recoil or explosive gases. In doingthis, the action pulls the wire link forwardly which in turn pulls onthe rear of the action spring, bringing it forward and thus compressingit. As the action reaches its rearmost or breech open position (FIG. 2),the action spring is compressed to its fully loaded position. Thecompressed action spring then pulls on the wire link which in turn pullsthe action forward and returns it to the forward-most or breech closedposition (FIG. 1).

The above system is described as using one wire link. It should also benoted that two wire links could be used, having one on either side ofthe gun and both being the mirror image of the other.

What is claimed is:
 1. In a firearm having a barrel, a chamber in saidbarrel for receiving a cartridge, a receiver frame attached to saidbarrel and a gun stock attached to said frame, a breech bolt meansmounted in said frame for reciprocable movement between a forward breechclosing position and a rearward breech open position, action springmeans mounted in said gun stock, and flexible wire means connected atone end to said action spring means and at the other end to said boltmeans, a stationary guide means mounted on said frame for guiding saidwire means so that upon rearward movement of said bolt means into breechopen position, said spring means is biased to resist the rearwardmovement of said bolt means and to urge the bolt means forwardly intobreech closed position.
 2. In a firearm having a barrel, a chamber insaid barrel for receiving a cartridge, a receiver frame attached to saidbarrel and a gun stock attached to said frame, a breech bolt meansmounted in said frame for reciprocable movement between a forward breechclosing position and a rearward breech open position, action springmeans mounted in said gun stock, and flexible wire means connecting saidaction spring means and said bolt means so that upon rearward movementof said bolt means into breech open position, said spring means isbiased to resist the rearward movement of said bolt means and to urgethe bolt means forwardly into breech closed position, a forward guidemeans mounted on said frame forwardly of the connection of said flexiblewire means to said breech bolt means, rear guide means mounted on saidframe between said forward guide means and said action spring means,said flexible wire means being operatively connected to said bolt meansand extending forwardly therefrom to run over said forward guide means,where said wire means makes a 180° turn to run rearwardly along saidframe and on said rear guide means and finally being connected to saidaction spring means.
 3. In a firearm as recited in claim 2 wherein saidaction spring means comprises an action spring tube mounted in said gunstock, an extension action spring positioned in said tube, said springhaving its rear end connected at the rear of the action spring tube andits forward end connected to the rear end of said flexible wire means sothat upon rearward movement of said breech bolt means to the breech openposition, the flexible wire means is pulled forwardly to place theaction spring in tension.
 4. In a firearm as recited in claim 2 whereinsaid action spring means comprises an action spring tube mounted in saidgun stock, a compression action spring positioned in said tube, saidcompression spring having its forward end supported at the front of saidtube and its rear end connected to the rear end of said flexible wiremeans so that upon rearward movement of said breech bolt means to thebreech open position, the flexible wire means is pulled to put theaction spring in compression.
 5. In a firearm as recited in claim 2wherein said flexible wire means is coated with a plastic material. 6.In a firearm as recited in claim 5 wherein said plastic material isnylon.
 7. In an automatic firearm having reciprocable action bars and abolt assembly connected thereto, an action spring located rearwardly ofsaid action bars and bolt assembly, a system for transferring the forceof the action spring to the action bars and bolt assembly comprising: aflexible wire link connecting said action spring and said action barsand bolt assembly, guide means guiding the movement of said flexiblewire link so that upon rearward movement of said action bars and boltassembly to breech open position, said flexible wire link moves to biassaid action spring which then tends to pull the flexible wire and thusurge the action bars and bolt assembly forwardly into breech closingposition.
 8. In an automatic firearm as recited in claim 7 wherein saidaction spring is an extension spring which is put in tension by therearward movement of said action bars and bolt assembly.
 9. In anautomatic firearm as recited in claim 7 wherein said action spring is acompression spring which is put in compression by the rearward movementof said action bars and bolt assembly.
 10. In an automatic firearm asrecited in claim 7 wherein said flexible wire link is coated withplastic material.